Answer:
[tex]-\frac{9}{r^4}[/tex]
Step-by-step explanation:
Using Power rule
[tex]\frac{d}{dr} (r^n)=nr^{n-1}\\-\frac{9}{r^4}[/tex]
The answer is F'(r) = [tex]\mathrm {-\frac{9}{r^{4}}}[/tex].
We can rewrite the function as :
F(r) = 3r⁻³
Now, differentiate by power rule :
F'(r) = (-3)3r⁻³⁻¹
F'(r) = -9r⁻⁴
F'(r) = -9/r⁴
